Apparatus for forming pulse jets of liquid

ABSTRACT

Apparatus for forming pulsed jets of liquid. A pressure cylinder cooperates with a barrel inlet end to define a charge chamber. With the pressure cylinder in its normal position, the barrel inlet opening is blocked. Upon actuation of the device, the pressure cylinder is forced toward the barrel inlet end, applying pressure to charge material within the charge chamber, until the barrel outlet opening is unblocked and the pressurized charge material is expelled through the barrel as a pulsed jet.

United States Patent 91 Hall em.

1541 APPARATUS FOR FORMING PULSE JETS OF LIQUID [75] Inventors: James M.Hall, Gaithersburg, Md.;

Louis L. Cllpp, McLean, Va.

[73] Assignee: Exotech Incorporated, Gaithersburg,

[22] Filed: April 19, 1971 [2]] Appl. No.: 135,120

521 U.S.Cl. ..239/102 511 Int. Cl. ..B05b 3/14 58 FieldofSearch..239/99,101,102,329,456,

[56] 7 References Cited UNITED STATES PATENTS 2,912,169 11/1959 Peffer..239/99 X 3,343,794 9/1967 Voitsekhowsky ..239/101 3,387,782 6/1968Mizuno ..239/l01 X 51 Jan. 2, 1973 3,490,696 1/1970 Cooley ..239/l0l3,520,477 7/1970 Cooley ....239/10I 3,521,820 7/1970 Cooley ..239/l0lPrimary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Edwin D. Grant Att0rneyMorton, Bernard, Brown,Roberts & Sutherland [57] ABSTRACT Apparatus for forming pulsed jets ofliquid. A pressure cylinder cooperates with a barrel inlet end to definea charge chamber. With the pressure cylinder in its normal position, thebarrel inlet opening is blocked. Upon actuation of the device, thepressure cylinder is forced toward the barrel inlet end, applyingpressure to charge material within the charge chamber, until the barreloutlet opening is unblocked and the pressurized charge material isexpelled through the barrel as a pulsed jet.

7 Claims, 12 Drawing Figures INVENTORS' M. HALL 8| CLIPP AT'I'OR 55SHEET 1 BF 3 mm vv aanssaud k wi Wa a/h; 64mm NM Z? Hlll PATENTEDJAN2191a PATENTED 21975 3.708.121

SHEEI 3 [IF 3 INVENTORS JAMES M. HALL 8:

LOUIS CLIPP ATTORNEYS .charge techniques have been used, but the expenseand hazard associated with explosive materials have limited their use.Piston expulsion of liquid is utilized in apparatus in which a piston isactuated to contact a liquid charge, expelling the charge from theapparatus at a I high velocity and pressure. Such apparatus knownheretofore have required considerable energy to create the necessaryhigh velocity and pressure in the liquid jet.

The present invention is directed to an apparatus for generating pulsedjets of liquid in which a piston is actuated to move a pressure cylinderfrom its rest position in which the liquid outlet is blocked to a secondposition in which the liquid outlet is opened, permitting the liquid todischarge. During the time the cylinder is moving, pressure is built upon the liquid charge material, and when this pressure reaches thedesired level, the outlet is opened to discharge the pulsed liquid jetat the desired velocity and pressure. As a consequence, the desiredvelocity and pressure are obtained with minimum expenditure of energy.Pressures of 300,000 to 500,000 p.s.i. are obtained with the presentinvention.

These and other aspects and advantages of the present invention are moreapparent in the following detailed description and claims, particularlywhen considered in conjunction with the accompanying drawings in whichlike parts bear like reference numerals. In the drawings:

FIG. 1 is a fragmentary sectional viewof apparatus in accordance withthe present invention;

FIG. 2 is a fragmentary view taken along line 2-2 of FIG. 1; j

FIG. 3 is a pressure-time diagram of the charge material within theapparatus as the apparatus is actuated.

FIGS. 4(a) and 4(b) illustrate the use of a deflection plate withapparatus in accordance with the present in vention;

FIGS. 5(a) and 5(b) illustrate an alternative means for deflecting thejet produced by apparatus of this invention;

FIGS. 6(a) and 6(b) illustrate apparatus of this invention designed toproduce multiple jets;

FIG. 7 illustrates apparatus of this invention includ ing means forflushing the jet nozzle to prevent plugging; and

FIGS. 8(a) and 8(b) illustrates apparatus of this invention designed forunderwater use.

As depicted in FIG. 1, a preferred embodiment of apparatus in accordancewith the present invention includes an elongated cylindrical housing 10having an elongated barrel 12 positioned within it. Barrel 12 includes amiddle portion l4of an enlarged diameter which fits snugly withinhousing 10, an elongated forward portion 16 of a relatively smalldiameter, and a rear portion 18 also of a small diameter substantiallythe same diameter as that of forward portion 16. Axial bore 20 passesthrough barrel l2 and serves as an acceleration path for pulsed jets ofliquid. Preferably, bore 20 tapers from a larger diameter in rearportion 18 to a smaller diameter in forwardl portion 16 so that asliquid charge travels through bore 20 the charge velocity and pressureincrease. End cap 22 is fastened to the rearward end of barrel 12, forexample, by means of bolt 24.

A radial bore 26 passes through housing 10 and into central portion 14of barrel 12. Within central portion 14 radial bore 26 intersectslongitudinal bore 28 which passes through rear portion 18 of barrel l2and communicates with bore 30 through end cap 22. For a small distancewithin barrel 12 and cap 22 and adjacent the interface of those twocomponents bore 28 and 30 have a slightly increased diameter withinwhich is positioned check valve 32. Bushing 34 retains check valve 32 inthis area. Bore 20 does not pass longitudinally through cap 22, butinstead, as seen in FIG. 2, at the intersection of barrel l2 and cap 22,bore 20 intersects with radial bore 36 that passes completely throughcap 22.

Pressure cylinder 38 includes a forward portion 40, encircling rearwardportion 18 of barrel l2, and a rearward portion 42 enclosing cap 22 butleaving a small chamber 44 to the rear of cap 22. Chamber 44 has adiameter slightly greater than the diameter of cap 22 and barrelrearward portion 18. This increased diameter extends forward about cap22 to a point about at the longitudinal midpoint of cap 22 at whichlocation chamber 44 ends and pressure cylinder 38 contacts cap 22 atcircumference 45, usually through an intermediate layer of fluid.Pressure cylinder 38 does not contact central portion 14 of barrel 12but instead a small chamber 46' is present between pressure cylinder 38and central portion 14. Preferably, chamber 46 has a longitudinaldimension slightly smaller than the longitudinal dimension of chamber 44to avoid direct contact at cap 22. Thus, pressure cylinder 38 is able tomove from its rearward position, as depicted in FIG. 1, to a forwardposition in which forward portion 40 of pressure cylinder 38 contactscentral portion 14 of barrel 12 before rearward portion 442 can contactcap 22. Pressure cylinder 38 is biased to its rearward position asdepicted in FIG. 1 by means such as spring 50 which is engaged betweenhousing 10 and pressure cylinder 38. Seal 48 is positioned betweenrearward portion 18 of barrel 12 and forward portion 40 of pressurecylinder 38 to provide a substantially fluid-tight seal. Seal 48comprises a rigid, non-resilient member 47, such as metal, whichsealingly engages portion 18, a resilient member 49 and a chamfer ring51. Member 47 has a lip 47' and resilient member 49 rests on this lip sothat it does not engage portion 18. In use, pressure is exerted uponmember 49 by fluid in the interface between portion 18 and portion 40which passes through gap 49' and, as a consequence, resilient member 49exerts a force on member 47, particularly lip 47', to seal member 47against portion 18. Camfer ring 51 prevents extrusions of member 49 intothe interface between member 47 and portion 40.

Forward portion 16 of barrel 12 is encircled by cylinder 52 which has anouter diameter substantially the same as central portion 14. Retainer 54retains barrel l2 and cylinder 52 within housing 10.*Barrel 12 isadditionally keyed within housing and cylinder 52 to prevent rotation.

Piston 56 is positioned behind pressure cylinder 38 and is surrounded byjacket 58 within which it fits snugly but slidingly. Housing 10 has onits outer surface adjacent jacket 58 an elongated recess 60, andretainer 62 within recess 60 maintains housing 10 and jacket 58 togetherwhile permitting longitudinal movement therebetween from the position ofFIG. 1 to a position in which retainer 62 is at the rearward end 64 ofrecess 60.

When it is desired to generate pulsed liquid jets, liquid chargematerial is introduced through inlets or bores 26 and 28. The pressureof this charge causes it to pass check valve 32 and to flowthrough bore30 into charge chamber 44. Piston 56 is then actuated to impact againstpressure cylinder 38. The pressure cylinder moves forward, applyingpressure to the charge material within chamber 44. FIG. 3 depicts thispressure on the charge within chamber 44 as a function of time. Pressurecylinder 38 is dimensioned so that as it moves forward, therebyincreasing the pressure on the charge in zone 44, circumference 45passes bore 36 as the pressure is at its optimum value, depicted atpoint 66 in FIG. 3. Once circumference 45 has cleared bore 36, thecharge material enters barrel bore 20, so that the pressure on thecharge material reaches a peak and then drops off as illustrated in FIG.3. The charge material is then expelled from barrel 12 as a pulsedliquid jet. Pressure cylinder 38 continues to move forward against thebias of spring 50 until the pressure cylinder contacts central portion14 of barrel 12. This impact is transmitted through central portion 14and cylinder 52, and so the forward end of cylinder 52 also impactsagainst the material at which the pulsed liquid jet is directed. Thisadditional impact causes a further fracturing of the material. Theforward motion of barrel l2 and cylinder 52 carries with thesecomponents housing 10 which moves with respect to jacket 58 untilrearward end 64 of groove 60 is against retainer 62.

A small amount of charge material is forced backward through check valve32 just prior to check valve 32 closing. This charge flow can beadjusted so that the volume of charge material within zone 44 is uniformfor each firing of the apparatus. Piston 56 can be actuated by anysuitable means such as an explosive charge, release of a pressurizedfluid, release of a cooked spring, etc. If desired, piston 56 andpressure cylinder 38 can be formed as one piece.

FIGS. 4(a) and (b) and 5(a) and (b) illustrate two embodiments of thisinvention having attachments for angling the fluid jet produced by theapparatus of this invention. In each embodiment, the device forproducing the fluid jet, generally designated by reference numeral 200,may be a device such as illustrated in FIG. 1. As shown in FIGS. 4(a)and (b), a deflection plate 201 is attached to the end of device 200 bya support mechanism 202. This deflection plate is arranged at an angle ato the fluid jet and contains slot 204. When using a deflection plate201, the fluid jet will be deflected in the form of a spray. The widthof the spray is determined by the width of slot 204 and may becontrolled to provide a jet suitable for cutting a slot. Angle a may beas great as 15 to FIGS. 5a and 5b illustrates an alternative embodimentin which cap 208 is attached to the end of device 200. In thisembodiment cap 208 has a number of bores 210 arranged therein in conicalfashion about a central opening 212 which is arranged co-axially withthe expulsion bore 20 in device 200. In this embodiment as the jet ofwater passes through cap 208 it is deflected in bore 212 to pass throughbores 210. The number of bores 210 can vary from one to any number,e.g., six as shown.

FIGS. 6(a) and (b) illustrate an embodiment of the device identical withFIG. I accept for the inclusion of a plurality of expulsion bores 20. Asshown in FIG. 6( a) there are two bores 36 passing through end cap 22and each bore 36 has two expulsion bores 20 perpendicular to andinterconnected therewith.

FIG. 7 illustrates another embodiment of the apparatus of this inventionand differs from FIG. 1 in providing a means for flushing expulsion bore20 to prevent plugging. In this embodiment end cap 22 of FIG. I issubstantially elongated as shown by end cap 122 in FIG. 7. Additionally,chambers 144 and 146, which correspond to chambers 44 and 46 in FIG. 1,are substantially enlarged. The device of FIG. 7 operates the same asthe device of FIG. 1, described above, except that in its end positionpressure cylinder 38 and seal 48 have moved to a third position to theright of bore 136 so that chamber 146 is connected through bore 136 withbore 120. Chamber 146 has connected therewith fluid pressure line 175which contains check valve 177. Check valve 177 operates upon a reducedpressure in chamber 146 to permit the introduction into this chamber offluid under pressure, e.g., air or water. Fluid passes through bore 136to flush bore 120. As pressure cylinder 38 returns to its normalposition, the pressure in chamber 146 will build up to close check valve177. The pressure in chamber 146 is balanced to allow return of pressurecylinder 38 to a position for operation of the jet valve 32.

FIGS. 8(a) and (b) illustrate a further embodiment of this devicedesigned for operation under water. In this device cylinder 52 whichsurrounds portion 16 of barrel 12 is elongated to form chamber forwardof portion 16. An air pressure line 220 is connected'with chamber 80. Inoperation under water, chamber 80 is always maintained at a sufficientpressure to prevent water, or other fluid media, from entering chamber80. Cylinder 52 may rest against the surface to be worked and impactthis surface at the same time as the pulsed liquid jet. FIG. 8 alsoillustrates the attachment of breaking tools 222 which may be of anyconventional shape. Breaking tools 222 causes further fracturing of thematerial being enclosed upon by the additional impact of cylinder 52.The end of portion 16 may be positioned such that the fluid jet mustpenetrate one to three inches of water but greater distancessubstantially reduce the velocity of jet.

Although the present invention has been described with reference topreferred embodiments, numerous modifications and rearrangements couldbe made and still the result would be within the scope of the invention.

What is claimed is:

1. Apparatus for forming pulsed jets of liquid comprising:

an elongated cylindrical expulsion barrel having an inlet end, an outletend and at least one longitudinal bore therethrough from the inlet endto the outlet end;

an end cap having a forward face connected to said expulsion barrelinlet end, having a rear face, and having at least one radial boretherethrough communicating with said expulsion barrel longitudinal bore;

bias means;

a pressure cylinder encircling said expulsion barrel inlet end and saidend cap and under urging of said bias means normally assuming a firstposition in which said pressurecylinder cooperates with said end cap todefine a charge chamber extending behind said end cap rear face andaround said end cap to a point intermediate said radial bore and saidend cap rear face and capable of movement to a second position in whichsaid charge chamber extends around said end cap to a point forward ofsaid radial bore;

said expulsion barrel and said end cap having an inlet openingtherethrough communicating with said charge chamber;

a check valve within the inlet opening for permitting charge flowthrough the inlet opening into the charge chamber while substantiallypreventing charge flow from the charge chamber throughthe inlet opening;and

actuating means for actuating said pressure cylinder to move saidpressure cylinder against the urging of said bias means toward said endcap, thereby applying pressure on charge material within the chargechamber until the pressure cylinder reaches the second position andcharge is expelled out the expulsion barrel as a pulsed liquid jet.

2. Apparatus as claimed in claim 1 further comprising a further cylinderencirclingly engaged about said expulsion barrel, a jacket slidinglyengaging said actuating means and said pressure cylinder, and retainingmeans for retaining said jacket relative to said expulsion barrel andsaid further cylinder while permitting limited longitudinal movementtherebetween, whereby upon actuation of said pressure cylinder, saidexpulsion barrel and said further cylinder move longitudinally withrespect to said jacket.

3. Apparatus as claimed in claim 1 further comprising flushing means forflushing said expulsion barrel after expelling of the pulsed liquid jet.

4. Apparatus as claimed in claim 3 wherein the flushing means comprisessaid pressure cylinder and expulsion barrel which cooperate to form asecond chamber, said pressure cylinder having a third position assumedupon the application of pressure on the charge material following thefirst and second position and expulsion of the liquid jet in which thirdposition the second chamber communicates through said radial bore withthe expulsion barrel and means for supplying pressure fluid to saidsecond chamber when the pressure cylinder is in said third position.

5. Apparatus as claimed in claim 1 further comprising a deflection plateattached to the outlet end of said expulsion barrel at an angle to thelongitudinal bore.

6. Apparatus as claimed in claim 1 further comprising a cap attached tothe outlet end of the expulsion barrel, said cap containing at least onebore therein interconnecting with the longitudinal bore at an angle tothelaxis of said longitudinal bore.

. Apparatus as claimed in clanm 1 wherein said barrel contains aplurality of longitudinal bores communicating with the radial bore.

1. Apparatus for forming pulsed jets of liquid comprising: an elongatedcylindrical expulsion barrel having an inlet end, an outlet end and atleast one longitudinal bore therethrough from the inlet end to theoutlet end; an end cap having a forward face connected to said expulsionbarrel inlet end, having a rear face, and having at least one radialbore therethrough communicating with said expulsion barrel longitudinalbore; bias means; a pressure cylinder encircling said expulsion barrelinlet end and said end cap and under urging of said bias means normallyassuming a first position in which said pressure cylinder cooperateswith said end cap to define a charge chamber extending behind said endcap rear face and around said end cap to a point intermediate saidradial bore and said end cap rear face and capable of movement to asecond position in which said charge chamber extends around said end capto a point forward of said radial bore; said expulsion barrel and saidend cap having an inlet opening therethrough communicating with saidcharge chamber; a check valve within the inlet opening for permittingcharge flow through the inlet opening into the charge chamber whilesubstantially preventing charge flow from the charge chamber through theinlet opening; and actuating means for actuating said pressure cylinderto move said pressure cylinder against the urging of said bias meanstoward said end cap, thereby applying pressure on charge material withinthe charge chamber until the pressure cylinder reaches the secondposition and charge is expelled out the expulsion barrel as a pulsedLiquid jet.
 2. Apparatus as claimed in claim 1 further comprising afurther cylinder encirclingly engaged about said expulsion barrel, ajacket slidingly engaging said actuating means and said pressurecylinder, and retaining means for retaining said jacket relative to saidexpulsion barrel and said further cylinder while permitting limitedlongitudinal movement therebetween, whereby upon actuation of saidpressure cylinder, said expulsion barrel and said further cylinder movelongitudinally with respect to said jacket.
 3. Apparatus as claimed inclaim 1 further comprising flushing means for flushing said expulsionbarrel after expelling of the pulsed liquid jet.
 4. Apparatus as claimedin claim 3 wherein the flushing means comprises said pressure cylinderand expulsion barrel which cooperate to form a second chamber, saidpressure cylinder having a third position assumed upon the applicationof pressure on the charge material following the first and secondposition and expulsion of the liquid jet in which third position thesecond chamber communicates through said radial bore with the expulsionbarrel and means for supplying pressure fluid to said second chamberwhen the pressure cylinder is in said third position.
 5. Apparatus asclaimed in claim 1 further comprising a deflection plate attached to theoutlet end of said expulsion barrel at an angle to the longitudinalbore.
 6. Apparatus as claimed in claim 1 further comprising a capattached to the outlet end of the expulsion barrel, said cap containingat least one bore therein interconnecting with the longitudinal bore atan angle to the axis of said longitudinal bore.
 7. Apparatus as claimedin claim 1 wherein said barrel contains a plurality of longitudinalbores communicating with the radial bore.